This follows the former premier's action in cooperating with the Opposition in signing a 'Citizen's Declaration' on March 4 which called for the resignation of Datuk Seri Najib Razak as Prime Minister.
The Prime Minister's Office (PMO) had initially said Dr Mahathir must follow democratic process and await the next election if he wants a change of PM.
But today, a media statement by the PMO read: "The Cabinet today discussed the actions of former Prime Minister Tun Dr Mahathir Mohamad, particularly in launching the so-called "Citizen’s Declaration" with opposition leaders last week.
"The declaration aims to topple the democratically-elected Government led by the Prime Minister, and is therefore against the law and the Federal Constitution.
"The Cabinet decided that, since Tun Mahathir is no longer supporting the current Government, he should no longer hold any position related to the Government.
"Therefore, the Cabinet today agreed unanimously to terminate the appointment of Tun Mahathir as advisor to Petronas."
Dr Mahathir had been appointed as Petronas adviser after he announced his retirement as prime minister in 2003.
In December 2013, Dr Mahathir had stated his intention to resign from the post, citing health reasons.
However, Najib at the time had advised the former UMNO president to stay on.
![The media statement released by the PMO today](http://img.astroawani.com/2016-03/81457693623_freesize.jpg)
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